Time Function (time_function)
A time function (time_function
)
is a function that
is applied to time or time stamp values, or that supplies a time or time stamp
value as a result.
Syntax
<time_function> ::=
ADDTIME(<time_or_timestamp_expression>,<time_expression>)
| MAKETIME(<hours>,<minutes>,<seconds>)
| SUBTIME(<time_or_timestamp_expression>,<time_expression>)
| TIMEDIFF(<time_or_timestamp_expression>,<time_or_timestamp_expression>)
<time_or_timestamp_expression> ::=
<expression>
<time_expression> ::=
<expression>
<hours> ::=
<expression>
<minutes> ::=
<expression>
<seconds> ::=
<expression>SQL Tutorial, Date and Time Calculations
When used in a function, the argument time_or_timestamp_expression
must
supply a time
value, a time
stamp value, or an alphanumeric value that matches the current
time or time stamp format. In a function, the argument time_expression
must
supply a time value or an alphanumeric value that matches the current time
format. When used in a function, each of the arguments hours
, minutes
or seconds
must be an integer greater than or equal to 0
.
If an expression is not an integer, decimal places are truncated.
Date and time values are available in a variety of date and time formats (ISO
, USA
, EUR
, JIS
, INTERNAL
). In the ISO
and USA
formats,
the hours are displayed modulo 24
. In the EUR
and JIS
formats, a number of hours greater than 99
causes
an error. In the INTERNAL
format, you can specify
up to 9999
hours.